This invention relates to compositions comprising a blowing agent and a polyol, commonly referred to in the art as B-side compositions or blends, and use of such compositions to produce polyurethane and polyisocyanurate foams ("PUR/PIR foams"). More particularly, the invention relates to such blends, foaming processes and polyisocyanate-based foams which utilize blowing agent compositions comprised of 2-chloro-1,1,1,2-tetrafluoroethane ("HCFC-124" or "124").
Polyisocyanate-based foams are well known in the art in a variety of forms for a variety of purposes, including, for example, as roofing and siding insulation in building construction and as insulation in the manufacture of domestic and industrial refrigerators and freezers. The foams are typically produced by reaction of a polyisocyanate with a polyol, in the presence of a blowing agent. Historically, chlorofluorocarbons such as CFC-11 have been the blowing agents of choice. These materials, however, are being phased out for their possible involvement in affecting the stratospheric ozone and in global warming.
Various alternative blowing agents have been proposed, including gaseous blowing agents such as 142b, 134a and 134, use of the latter, for example, having been disclosed in WO 98/03580. The major drawback of these alternatives is the elevated pressure generated when they are blended with polyols because of their relatively low solubility. What is needed is a gaseous blowing agent which has superior solubility characteristics in polyols and is therefore easier to use than other low boiling blowing agents.
HCFC-124 is disclosed in U.S. Pat. No. 4,972,003 and WO 91/14732 as a blowing agent, but not exemplified. JP 57040533 discloses HCFC-124 as a blowing agent, but only exemplifies its use for co-blowing with CFC-11.